Professions glitch

We are currently aware of these issues. You'll want to keep up to date on it by checking out our sticky. >^.^<

Patch 4.0.1 - Issues and Updates
http://forums.worldofwarcraft.com/thread.html?topicId=27188062708&sid=1

In the mean time, you should be able to access crafting professions by typing the following:

/cast ProfessionName

or in your case

/cast Alchemy

I'm afraid we don't currently have a fix or workaround for gathering professions at this time. =>.<=

Q u o t e:
And what do we do if that doesn't work?

I'm afraid I don't have any other workarounds to provide at this time, though you may want to give a full Reset UI a shot.

Reset UI
http://us.blizzard.com/support/article/20377

Q u o t e:
My problem is that I can't open the crafting window at all, and so thus cannot link it.

If you type /cast skillname in the command line, that usually pops open the crafting window.

Example /cast alchemy /cast tailoring, etc.

Q u o t e:
Sadly if his window is entirely defunct so is the command. Reports concur this to being true. The cast sequence will align itself with some other arbitrary item. For example /cast alchemy when the window is defunct causes "Not enough rage" .. and still no window.

Oh my goodness. And you have fully reset your UI?

To do a full reset UI, you will want to save your addons in another spot if you wish to preserve them.

Then rename/delete or move your WTF, Cache and Interface folders while WoW is shutdown. Reboot your system.

Note, if you are running Vista make sure your permissions are set so it does not undo your changes.

More detailed instructions for different operating systems, including Macs are here.

http://us.blizzard.com/support/article.xml?articleId=18761&searchQuery=reset%20UI&pageNumber=1

While these workarounds work for a great many - if you find they do not AFTER you have done a full and proper reset UI (and without addons), please submit a petition ingame so our Game Masters can look into your particular case further.

I'd also recommend noting that you've already done a full reset UI so the Game Master knows you are past that step.

To do a full reset UI, you will want to save your addons in another spot if you wish to preserve them.

Then rename/delete or move your WTF, Cache and Interface folders while WoW is shutdown. Reboot your system.

Note, if you are running Vista make sure your permissions are set so it does not undo your changes.

More detailed instructions for different operating systems, including Macs are here.

http://us.blizzard.com/support/article.xml?articleId=18761&searchQuery=reset%20UI&pageNumber=1